The present invention relates to an electronic accounting machine having a memory for storing information characters comprising data and instructions, a central unit for executing the operations commanded by the instructions on the data, a keyboard for introducing information into the memory, and an alphanumeric line display for visually displaying at the most one line of the said information.
With the introduction of microprocessors on the computer market, attempts have been made to facilitate communication between man and machine. More particularly, in recent years, the display has become ever more sophisticated in order to display as clearly as possible the requests of the machine and as to avoid errors.
There are in existence at present data terminals having page displays which are capable of representing visually the format of an entire document in which each field of information which the operator must introduce is preceded by a corresponding heading, for example: "Name of customer . . . "; "Address . . . "; "Goods ordered . . . "; etc.
Obviously, it would be very uneconomical to have an electronic accounting machine comprising a page display of the above-mentioned type. On the contrary, electronic accounting machines comprise alphanumeric displays of small capacity (usually from 20 to 60 characters) which must contain all the messages necessary for a certain job (that is, a certain program).
Known accounting machines use a line display wherein the various messages are presented in succession.
The disadvantage of these machines consists in the fact that the operator sees alternately the operator guiding message sent by the machine and the characters in the stage of introduction and therefore does not have the possibility of seeing simultaneously the guide message and the characters introduced by means of the keyboard.